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hobomoe
Jun6-11, 07:16 PM
1. The problem statement, all variables and given/known data
Acidified potassium dichromate is an oxidant. It will react with titanium metal which is oxidised to form titanium ions.

Show that Ti^3+ and not Ti^2+ is formed in the reaction. Your answer should include chemical equations for any possible reactions and justification for you conclusion based of E values.

E(Cr207^2-/Cr^3+)=+1.33v E(Ti^2+/Ti)=-1.63v E(Ti^3+/Ti^2+)=-2.32v


2. Relevant equations
E(Cr207^2-/Cr^3+)=+1.33v E(Ti^2+/Ti)=-1.63v E(Ti^3+/Ti^2+)=-2.32v


3. The attempt at a solution
E(Cr207^2-/Cr^3+)-E(Ti^2+/Ti)=2.96v
E(Cr207^2-/Cr^3+)-E(Ti^3+/Ti^2+)=3.65v
Dichromate ions react with the titanium metal to form Ti^2+ ions. These ions then react with remaining dichromate ions to form Ti^3+ ions. It will try to form Ti^3+ ions from the Ti^2+ ions in order to get a greater E value.

hobomoe
Jun7-11, 12:01 AM
zzz so many views and no answer

Borek
Jun7-11, 04:11 AM
E(Ti^3+/Ti^2+)=-2.32v

And not -0.37V?

What I don't like about the question is that pH is not given. Or at least it should state standard conditions.

hobomoe
Jun7-11, 04:37 AM
Acidified potassium dichromate, so its acidic. Don't need to go super indepth, it's only final highschool year redox.